MECHANICAL PROPERTIES OF HIGH STRENGTH CONCRETE AT HIGH TEMPERATURES

Abstract

The mechanical properties of high strength concrete at high temperature have been studied experimentally. The compressive tests were carried out on three grades of concrete with standard design compressive strengths of 21,42 and 60MPa, respectively. The stress-strain curves for high strength concrete are quite different from those of normal strength concrete. For higher strength concrete under heating conditions below about 300℃, the initial slope is steeper, and the limit of linear response shows a higher percentage of the compressive strength. Also, the compressive strength decreases below 100℃ during heating, increases up to about the same strength of room temperature below 200℃ and gradually decreases with further increase of temperature